BORIS Johnson last night backed David Cameron as he made a spectacular arrival in Birmingham.

The hugely popular Conservative brought the place to a standstill as he arrived to chants of “Boris, Boris” from passers-by.

Speaking at a rally of almost 1,000 Tory activists last night, Mr Johnson vowed to support Mr Cameron through the 2015 election.

He said: “No one as a result should have any cause to doubt my admiration for David Cameron.”

He stressed he was one of the first “Cameroons” in the 2005 Tory leadership contest.

“I believe that in tough circumstances he and George Osborne are doing exactly what is needed for this country and to clear up the mess left by Labour.”

His support for Mr Cameron – which comes amid feverish speculation about his prime ministerial ambitions – follows a warning from Tory heavyweight Ken Clarke for Mr Johnson to “get back to the day job”.

No one as a result should have any cause to doubt my admiration for David Cameron

Boris Johnson

In an attack at the Tory Party Conference yesterday, Mr Clarke said he thought the Mayor of London should “calm down” and insisted there was “not the remotest possibility” of a leadership vacancy.